Precision 7770 : Confused with M.2 slotnumbers and their capabilities in manuals

My Prec. 7770 came with 1 TB drive in the slot under the access door.

I successfully added 3 pieces 4 TB drives in the 3 empty slots and worked with all 4 drives.  Everything is ok.

Finally I wanted to change the origional 1 TB drive with a new Samsung 990 PRO.

It was externally added via USB and partitioned via the Win11 DriveManager programm.

But then :  Samsung Magigican didn't see it for cloning.

Win install from USB to USB can not work.

Change empty drive with 1 TB drive and install Win11 from USB...

Win Install doesn't see the Samsung either.

There are tables in the manuals about slot capabilities. But I can't read them. They confuse me in both versions German and English and do not shade light on my problem. Did anyone solve this before ?

Disabling the other drives in the BIOS did not help !